EVALUATION OF EPIDEMIC POTENTIAL OF WESTERN EQUINE ENCEPHALITIS-VIRUS IN NORTHEASTERN UNITED-STATES

  • 1 January 1976
    • journal article
    • research article
    • Vol. 49  (5) , 439-445
Abstract
The problem of evaluating the epidemic potential of western equine encephalitis in the northeastern USA is presented and possible reasons are discussed for the present lack of human and horse cases of this disease even though increased numbers of isolations of the virus have been obtained in the east during recent years. Epidemiologic factors of vector bionomics and virus strain variations are considered. While this virus strain can no longer be regarded as uncommon in the northeast, the evidence indicates there is little potential for epidemic expression of this agent in the human and horse population. This appears to be due to differences in the bionomics of the mosquito Culiseta melanura, which serves as the primary enzootic vector in the northeastern USA and in the bionomics of Culex tarsalis that is the vector in the western region of the USA. Other limiting factors in the epidemic potential may be variations between virus strains located in the east and west.